Organosilicon compounds

ABSTRACT

Organosilicon compounds, polymers and copolymers have been prepared containing acetylenic linkages between adjacent silicon atoms. The basic compounds are defined by the general formula R&#39;&#39;(R2Si)m(O*C)-(C*C) (SiR2)nR&#39;&#39;&#39;&#39; where R&#39;&#39; and R&#39;&#39;&#39;&#39; are each H, halogen, hydrocarbonoxy or -NQ2 as above defined, monovalent hydrocarbon or monovalent halogenohydrocarbon, m is 1 to 4, n is 0 to 4, R&#39;&#39;&#39;&#39; being H, alkyl, aryl or trihydrocarbylsilyl when n is 0. The polymers can be defined by the unit formula (OSiR2-C*CC*C-SiR2-) and may be copolymers containing units of the formula QaSiO4 a/2 where Q is monovalent hydrocarbon or halogenohydrocarbon and a is 0 to 3.

United States Patent 1 Chandra et al.

[ 1 Sept. 11, 1973 ORGANOSILICON COMPOUNDS [22] Filed: May 19, 1972 [2i] Appl. No.: 254,983

Related US. Application Data [62] Division of Ser. No. 59,701, July 30, 1970, Pat. No.

52 us. ci...'.'..' ..260/448.2" 260/465 P, 260/4482 D, 260/4488 R [51] 1m. Cl e07: 7/08, covr 7/l8 [58] Field of Search 260/4482 Q, 4482 D, zen/448.8 R

[56] References Cited UNITED STATES PATENTS 2,671,099 3/1954 Frisch et al. 260/4482 D Frisch et al 260/4488 R Chandra et al. 260/4482 0 3/1954 l2/l97l Primary Examiner-Daniel E. Wyman Assistant Examiner-Paul F. Shaver Att0rney-Robert F. Fleming, Jr. et al.

[57] ABSTRACT Organosilicon compounds, polymers and copolymers have been prepared containing acetylenic linkages beween adja tso at m -Th ha s mpo n r defined by the general formula R(R;Si)m(C C) (C C)(SiR ),.R" where R and R are each H, halogen, hydrocai'bonoiy or N'QYaKEbBVe defined, monovalent hydrocarbon 0r monovalent halogenohydrocarbon, m is l to 4, n is 0 to 4, R being H, alkyl, aryl or trihydrocarbylsilyl when n is 0. The polymers can be defined by the unit formula (OSiR2C C C C-SiRz) and may be copolymers containing units ofYlie formula Q,,SiO, 2 where Q is monovalent hydrocarbon or halogenohydrocarbon and a is 0 to 3.

5 Claims, No Drawings ()RGANOSILICON COMPOUNDS This application is a divisional application of U.S. Put. application Ser. No. 59,70l, filed July 30, 1970, issued Oct. I7, 1972, as U.S. Pat. No. 3,699,l4(), claiming Convention priority under 35 U.S.C. l l9, based on United Kingdom application No. 38,158/69, filed July 30, 1969.

This invention relates to organosilicon compounds containing acetylenic unsaturation and to a process for the preparation of such compounds. The invention also relates to the use of the said organosilicon compounds as intermediates in the preparation of cyclic and polymeric materials.

According to the invention, there are provided organosilicon compounds of the general formula R(R Si,,,(C E C) (C C) (SiR ),,R" wherein R and R each represent a hydrogen atom, a halogen atom, a hydrocarbonoxy radical or a radical of the formula NQ wherein each Q represents a hydrogen atom or a monovalent hydrocarbon radical, each R represents a hydrogen atom, a halogen atom or hydrocarbonoxy radical, a radical of the formula NQ a monovalent hydrocarbon radical or a monovalent halogenhydrocarbon radical, m is an integer from 1 to 4 inclusive, n is zero or an integer from 1 to 4 inclusive, R beinghydrogen, an alkyl radical, an aryl radical or a trihydrocarbylsilyl radical when n is zero.

In the general formula of the organosilicon compounds of this invention, R and R" each represent a hydrogen atom, a halogen atom, preferably chlorine or bromine, a hydrocarbonoxy radical or a radical of the formula NQ The term hydrocarbonoxy as used herein means any radical of the formula R"O in which R'" is a radical composed of carbon, hydrogen and, optionally, oxygen, any oxygen present in R" being in the form of ether linkages. Examples of such hydrocarbonoxy radicals are methoxy, ethoxy, propoxy, phenoxy, methoxyethoxy and ethoxybutoxy. The preferred hydrocarbonoxy radicals are those which are the most readily hydrolyzable, that is, those having less than eight carbon atoms. Examples of -NQ, radicals which may be represented by R and R" are NH,, --NHCH,, -N(C;H --NCH (CH CH=CH and NH(CH,C,H,,). Where Q is a monovalent hydrocarbon radical, it preferably has less than 19 carbon atoms.

The R radicals in the general formula may be any radical as exemplified for R and R" but, as hereinafter indicated, are preferably selected from monovalent hydrocarbon radicals and monovalent halogenohydrocarbon radicals, for example, alkyl and cycloalkyl radicals, e.g. methyl, ethyl, propyl, hexyl, decyl, octadecyl and cyclohexyl, alkenyl radicals, e.g. vinyl, ally] and cyclohexenyl, aryl radicals, e.g. phenyl, naphthyl, benzyl and tolyl and halogenoalkyl and halogenoaryl radicals, e.g. chloromethyl, trifluoropropyl and bromophenyl. Most preferred from considerations of commercial availability are compounds in which the R radicals are selected from methyl and phenyl radicals.

Depending on whether n is zero or an integer, the compounds represented by the general formula may contain one or two of the specified organosilyl radicals. When n is zero, R should represent a hydrogen atom or an alkyl, aryl or trihydrocarbylsilyl radical, for example, the methyl, ethyl, butyl, octyl, tetradecyl octadecyl, vinyl, allyl, phenyl, benzyl, trimethylsilyl, dimethylphenylsilyl and dimethylvinylsilyl radicals. Preferably, the said alkyl and aryl radicals and the hydrocarbyl radicals present in the trihydrocarbylsilyl group are those having less than 19 carbon atoms.

The compounds of this invention may he prepared by the reaction of I an acetylenic compound of the formula Li(C 5 C) (C 5 C)X, wherein X represents a hydrogen atom or a lithium atom with (2) one or more silanes of the general formula R(R Si),,Y, wherein Y represents a halogen atom, preferably chlorine, p represents an integer of from 1 to 4 inclusive and R and R are as hereinabove defined.

The acetylenic compound (1) may be prepared by the reaction of a lithium alkyl with diacetylene in the appropriate molar proportions. This reaction is best carried out at temperatures below about 0C. and most preferably at temperatures below about 20C. Most conveniently, the lithium acetylenic compound is prepared in situ in a suitable solvent just prior to contact with the silane reactant (2).

Reactant 2 may comprise a mixture of silanes of the general formula R'(R,Si),,Y. More preferably, however, a single silane is employed since this leads to a more completely defined product. Reactant 2 may be a monosilane or a polysilane and may be, for example, dimethylchlorosilane, diphenylmethoxychlorosilane, triethoxybromosilane, aminodimethylchlorosilane, dimethylamino(diphenyl)chlorosilane, noctadecylmethylmethoxybromosilane, methoxytetramethylchlorodisilane and methoxyethoxyoctamethylchlorotetrasilane.

The reaction between the lithium acetylene compound (l) and the silane (2) is best carried forward in the presence of one or more solvents for the reactants. Suitable solvents include, for example, benzene, toluene, xylene, n-hexane, diethylether, tetrahydrofuran and mixtures of two or more of these. The reaction may be performed at temperatures up to that at which the lithium acetylene compound decomposes, that is, up to or above 25C. A convenient temperature range for carrying out the reaction is from 10 to +5C. The reaction can be initiated by mixing the reactants (l) and (2) at such temperatures or alternatively the reactants may be mixed at lower temperatures and the temperature of the reaction mixture allowed to increase to achieve the desired reaction rate.

Compounds of this invention in which R and R" and optionally R, are halogen atoms may also be prepared from the corresponding compound in which R and, when present, R" and R is an amine group, e.g. the N(Ch:,), group or a hydrogen atom, by reaction of that compound with the anhydrous hydrogen halide or with the halogen respectively. Alternatively, they may be prepared by reaction of an acylhalide on the corresponding organosilicon compound wherein R, R" and R are alkoxy radicals.

The presence of the R, R" and optionally the R functional radicals in the compounds of this invention render the compounds useful as intermediates in the preparation of other organosilicon compounds and as crosslinking agents for organosilicon and organic systems. Compounds wherein R and optionally R" and one or more of the R substituents are halogen or lower alkoxy may be hydrolyzed to form disiloxanes and linear or crosslinked polymers. Of particular interest are those compounds wherein m and n are each unity, R and R are halogen atoms, preferably chlorine, and R is a monovalent hydrocarbon radical or monovalent halogenated hydrocarbon radical. Compounds of this type may be converted to novel polymers comprising the repeating unit [OSiR2C E C-C E C"S1Rz"] by hydrolysis of the compound and condensation of the hydrolysis product. Similarly, copolymers containing the specified unit may be obtained by the cohydrolysis of the organosilicon compound and one or more hydrolyzable silanes wherein any organic radicals bonded to silicon atoms are monovalent hydrocarbon or halogenated hydrocarbon radicals. Alternatively, the copolymers may be obtained by equilibration of the hydrolysis product with cyclic siloxanes according to known procedures. This invention includes organosilicon polymers having the repeating unit (OSiR -C E cC E cSiR and copolymers of from 0.1 to 99.9 percent by weight of such units and 99.9 to 0.1 percent by weight of units of the formula Q SiO wherein Q represents a monovalent hydrocarbon or halogenated hydrocarbon radical and a has a value of 0, 1, 2 or 3. Q may be any desired monovalent hydrocarbon or halohydrocarbon radical, e.g. alkyl, alkenyl, aryl, aralkyl, alkaryl, haloalkyl and haloaryl. Preferably, however, the Q substituents are selected from methyl, phenyl, vinyl and 3,3,3-trifluoropropyl radicals. The invention further includes cyclic organosilicon compounds of the general formula ]-O,,. -,R Si(C 5 C) SiR O,,. wherein R represents a monovalent hydrocarbon or halohydrocarbon radical. Such compounds may be obtained from the hydrolysis product of the compounds of this invention wherein m and n are each unity, R and R" are hydrolyzable and R is non-hydrolyzable by heating an organic solution of the said hydrolysis product to a temperature of from about 80 to 100C.

The homopolymers may be converted to an insoluble crosslinked material on heating in the presence of any of the organometallic compounds known to oligomerize or polymerize acetylenes, for example, molybdenum hexacarbonyl or dicobalt octacarbonyl. When heated to a temperautre of about 130 to 140C. in the absence of the carbonyl compound, the homopolymer in which the R radicals are methyl radicals has been found to convert to a light-brown glassy solid without significant change in molecular weight. On further heating to about 200 to 250C., a dark, glassy solventinsoluble solid is obtained which on thermogravimetric analysis indicates an ability to withstand temperatures of at least 700C. without significant loss of weight or change of appearance. The polymers of this invention, therefore, find application as high temperature resistant laminating and molding compounds and in the preparation of adhesives.

The following examples illustrate the invention. Example 1 n-butyllithium (17.2 g., 2 mol) in n-hexane (100 ml.) was added dropwise to a solution of diacetylene (6.73 g., 1 mol) in tetrahydrofuran (300 ml.) at 23C. with constant stirring. After the addition of n-butyllithium was completed (1% hr.), the system was stirred for a further period of approximately 2 hours and then slowly warmed to about to C. N,N-dimethylamino(dimethylchloro)silane (37.0 g., 2 mol) was then added dropwise and the reaction mixture was stirred for a further period of 6 to 8 hours at room temperature. The solvents were removed at 20/10 mm. and replaced by ether (200 ml.). The precipitated lithium chloride was filtered off and the filtrate on distillation afforded a white solid (33.9 g., 72.2%) b.p. 82 to 85/0.05 mm.

which was characterized as bis(N,N-dimethylaminodimethylsilyl)diacetylene. (Found: C, 56.1, H, 9.1; m/e 252. C H N Si requires C, 57.1; H, 9.5%, M 252').

'H NMR spectrum showed two singlets at 7.6 (NMe and 9.8 (SiMe integrated in the ratio of 1:1. Example 2 n-butyllithium (12.8 g.), diacetylene (5.0 g.) and methoxydimethylchlorosilane (24.9 g.) were reacted by the method of Example 1. The product was bis(methoxydimethylsilyl)diacetylene (7.5 g.), b.p. 72/0.7

Example 3 Employing the procedure of Example 1, nbutyllithium (6.9 g.), diacetylene (2.7 g.) and dimethylchlorosilane were employed to prepare bis(dimethylsilyl)diacetylene (5.9 g.) b.p. 73/1l mm. Example 4 Dry l-lCl gas was slowly bubbled into a solution of bis- (N,N-dimethylaminodimethylsilyl)diacetylene (17.6 g.) in n-pentane (200 ml.) at approximately 10. The passage of l-lCl gas was stopped after about 1 hour and the reaction mixture was filtered. The filtrate was concentrated at reduced pressure to afford a white crystalline solid (15.8 g., 96.3%) which was characterized as bis(dimethylchlorosilyl)diacetylene, b.p. 44 to 46/0.05 mm. (Found: C, 40.1; 1-1, 6.1; c l-l Cl si requires C, 40.85; H, 5.1%).

'H NMR of the above compound showed only one singlet at 9.34 (SiMe Example 5 Water (5 ml.) was added to a solution of bis(dimethylchlorosilyl)diacetylene (5.0 g.) in tetrahydrofuran (25 ml.) with constant stirring. An exothermic reaction ensued. The colorless reaction mixture was stirred overnight and then extracted with ether. The ether extract was concentrated under reduced pressure to afford a white powder (4.4 g.) which was characterized as l-l(OSiMe C CC CSiMe ),,Ol-l, m.p. (Found: C, 53.3;1-1, 7.2, required C, 53.3; H, 6.67%).

The molecular weight of the product by Vapour Phase Osmometry was 2,350 and differential thermal analysis of the product.showed a second order transition glass transition at 32 and a sharp melting endow therm characteristic of a crystalline polymer at +84". Example 6 0.81 g. of the polymer prepared in Example 5 was heated to 135C. for 3 t0 4 hours. A light-brown glassy I solid was obtained with no appreciable change in molecular weight and negligible weight loss. The solid was further heated at 210 to 230 for 2 to 3 hours to afford a hard dark reddish-brown solid, no appreciable loss in weight occurring during the heating step. Thermogravimetric analysis carried out on this material showed negligible loss in weight up to 700. Very little change in appearance of the polymer was observed. Example 7 0.70 g. of the polymer prepared in Example 5 and molybdenum carbonyl (0.1 g.) in heptane (7 ml.) gave a colorless solution at 60. On further heating to 1 10 (k hr.), the whole reaction mixture gelled to give a dark brown, insoluble mass. Example 8 1.4 bis(dimethylchlorosilyl)diacetylene (27 g.) was stirred into a solution of water (10 ml.) in tetrahydrofuran ml.) for 2 hours. Benzene (30 ml.) was then added and the Tl-lF/water/benzene azeotrope distilled off. The residue was dissolved in ether and dried over magnesium sulphate. Whitc crystals separated which were isolated and shown by infrared, nmr, u.v. and mass spectral studies to be the cyclic compound [O (CH Si(C C) Si(CH O mp 214C.

That which is claimed is:

1. Organosilicon compounds of the general formula R(R Si),,,(C E C)-(C E C) (SiR ),,R" wherein R and R" each represent a halogen atom or a hydrocarbonoxy radical of the formula R"O in which R' contains less than eight carbon atoms and is a radical composed of carbon and hydrogen or a radical composed of carbon, hydrogen and oxygen atoms wherein the oxygen atoms are present as ether linkages, each R represents a monovalent hydrocarbon or halohydrocarbon radical containing one to l8 carbon atoms, m is l,2,3or4andnis l,2,3or4.

2. Organosilicon compounds as claimed in claim 1 wherein m and n are each 1.

3. Organosilicon compounds as claimed in claim 1 wherein each R represents a methyl radical or a phenyl radical.

4. The compound bis(dimethylchlorosilyl)diacetylane.

5. The compound bis(methoxydimethylsilyl)diacetylene. 

2. Organosilicon compounds as claimed in claim 1 wherein m and n are each
 1. 3. Organosilicon compounds as claimed in claim 1 wherein each R represents a methyl radical or a phenyl radical.
 4. The compound bis(dimethylchlorosilyl)diacetylene.
 5. The compound bis(methoxydimethylsilyl)diacetylene. 